My brother and I installed the new spark plugs and the block heater. Plugs looked pretty good for having 128k miles on them. I don't think I'll be replacing them again, regardless of how long the car lasts.
The block heater was kind of an adventure. I put it in from the top since I was already removing the wiper assembly to do the plugs. While my brother was feeling around for the hole that I told him was about the size of his finger, he got his finger stuck in it.
He got it out after a couple minutes of panic. Getting the heater down to the hole requires some tricky maneuvering. I think I would recommend those with shorter arms install from the top, while longer and bigger arms would probably have an easier time from below. I have the cord sticking out of the upper grill for now. It took the coolant temp from ~50F to ~95F in about an hour. Can't wait to see how it handles some real cold.